Music legend, quincy jones caught in the middle of the battle between casino mogul, steve wynn, and "girls gone wild" creator, steve francis. He took the stand on thursday and said one of them isn't telling the truth. Reporter: It took music mogul quincy jones three words to answer the question that's consumed hollywood headlines for three days. Did you ever hear steve wynn threaten to kill joe francis? Absolutely not. Reporter: The ailing 79-year-old was the star witness in a civil suit, pitting las vegas casino mogul, steve wynn, against joe francis, founder of "girls gone wild." Francis says wynn threatened to kill him in an e-mail sent in 2010. An e-mail he says he learned about from the legendary music producer. Jones is friends with both men. And had even tried to help settle a gambling debt francis owes wynn's casino. I was trying to make peace. Reporter: But jones told jurors, francis' story was a, quote, naked lie. I keep hearing about e-mails. I've never seen anything. Reporter: He drew laughs when he was asked if he ever called wynn a gangster. That sounds like a line from "scar face." Reporter: Jones says he's been friends with wynn for 35 years. And though he's known francis for 12, and they live across the street, he admitted the two have a complex relationship. A lot of drama. Understood. I know my brother. Reporter: In an exclusive interview with kabc late thursday, francis maintained he's telling the truth. 100% I heard it. If quincy was trying to color his argument by saying it, you know, maybe he did. But he didn't come out and say that I was lying. Reporter: A question jurors will most likely begin answering later today. For "good morning america," amy robach, abc news, new york.

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